A sheet discharge sensor 4 has hitherto been provided in the vicinity of a pair of vertically-arranged discharge rollers 2, and the sensor is used for the purpose of detecting a trailing end of a sheet 1, and the like. FIG. 10A is a diagrammatic view of a related-art sheet detection mechanism, and FIG. 10B is a diagrammatic view of the sheet detection mechanism when viewed from the front in FIG. 10A. In the related art, when the sheet 1 is ejected from the front, the sheet 1 is conveyed, while deflected, under the influence of heat stemming from a heating roller 3; hence, there arises a problem of a decrease in the detection accuracy of the sheet discharge sensor.
Meanwhile, Japanese unexamined patent application publication No. JP-A-2003-76111 (Hereinafter, Patent Document 1) describes a related art image forming apparatus. In the related art image forming apparatus, when a toner pattern on a transfer belt is detected by means of a sensor, the sensor is disposed opposite the surface of a conveyor roller, thereby correcting surface waviness in the belt and performing detection. According to this configuration, it is possible to realize a stable detection of a toner pattern with superior accuracy.